Directions of two tails (plasma and dust tails) of a comet in comparison with the Sun and its orbit, with courtesy of Stellar Navigator 11/AstroArts. These diagrams show that the plasma tail extends to the quasi-antisolar direction and that the dust tail curves according to the orbit of the associated comets. While comets have plasma and dust tails, up to the relative angle with the Earth, two tails are visible (a) or apparently overlap with each other and cannot be distinguished by the terrestrial observers (b).